In recent years, as a laser strong instantaneous output power having a pulse width of femtoseconds has been developed, in order to generate an electric wave of a terahertz region, research is being conducted on terahertz electromagnetic wave generation that makes use of a uniaxial dielectric crystal, a semiconductor or a low-temperature superconductor used as an emitter of a terahertz region.
In this regard, a terahertz electromagnetic wave emitter is realized as an electromagnetic wave ordinary-temperature emitter that makes use of a zinc-cadmium-tellurium-based mono-crystal. In this connection, Korean Patent. Application Publication No. 2003-0095533 (published on Dec. 24, 2003) as a related art discloses an emitter which operates as a ultra-high speed element by generating a single shot signal of picoseconds or less, wherein the single shot signal has an ultra-wide signal band of about several terahertz in a direct current.
However, optical system is required to use a crystal. In an effort to supplement this problem, there has been used an FET-type terahertz emitter using a gate. In a semiconductor-type structure, however, due to the contact of a gate, the mobility of 2DEG channel may be reduced and the performance may be restricted depending on the channel length. Furthermore, in the case of an FET-type terahertz detector, there are required a boundary condition and an element structure different from those of an FET-type terahertz generator.